Swelling transition of a clay induced by heating
Författare
Summary, in English
Clays are of paramount importance for soil stability, but also in applications ranging from oil recovery to composites and hydrogels. Generically, clays are divided into two subclasses: macroscopically swelling, ‘active’ clays that have the capacity for taking up large amounts of water to form stable gels, and ‘passive’ or non-swelling clays; the former stabilize soils whereas the latter are known to lead to landslides. However, it has been unclear so far what mechanisms underlie clay swelling. Here, we report the first observation of a temperature-induced transition from a passive to an active, swelling clay. We propose a simple description of the swelling transition; while net attractive interactions are dominant at low temperatures so that the clay particles remain attached to each other in stacks, at higher temperatures it is energetically favourable for the clay to swell due to the entropy that is gained by counterions which are liberated during swelling.
Avdelning/ar
Publiceringsår
2012
Språk
Engelska
Publikation/Tidskrift/Serie
Scientific Reports
Volym
2
Dokumenttyp
Artikel i tidskrift
Förlag
Nature Publishing Group
Ämne
- Physical Sciences
- Natural Sciences
Nyckelord
- clays
- swelling
- X-ray scattering
- Rheology
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 2045-2322